TFT

My 2008 S8 is at the Audi dealership with a major coolant leak. I just got a call regarding the repair and was told the the intake flaps were making noise and that it was a matter of when, not if, there would be a failure and the result could be catastrophic.
I have directed them to replace the manifold.
Have any of you experienced this type of issue with your S8 V-10s?
Based on what I have read it is a fairly common problem.

ScottCNelson

Typically either the flaps break or the runners that open and close them do. Carbon build up can cause this, so you may well need a carbon clean and a new IMF. Be prepared to open your wallet, the IMF is $2,100 plus labor and a proper carbon clean is very labor intensive. A good Indy is indicated, but I guess it's too late for that. As far as "catastrophic" failure, I've never heard of IMF flaps causing the engine to grenade. If the flaps break off, they can fall unto the top of the valves and theoretically work their way into the combustion chamber, but no one has ever reported that happening. You will typically get poor performance, rough start, and CELs. A cheap bore-scope and VAG-COM would be helpful tools.

Turbo Tony

I had mine booked in for a carbon clean at an independent garage. I asked them to check the intake as soon as it was removed fo damage to the flaps. Sure enough, they were in pieces and I had to replace it.

TFT

The more I researched this the more common the problem seemed to be.
I bought a new intake manifold through AUDIUSAParts.com for $1,572.00. That was much cheaper than buying it from the Audi dealership.
Considering they already have the manifold removed am going to have them determine if a carbon cleaning is necessary and then do it if required.

ScottCNelson

...I've never known a dealer to let you provide the parts for a repair. Indies, yes, but never a dealer. The outrageous markup is baked into their profit and they won't warrant parts they didn't source, I've even found that the same part over the same dealer's retail parts counter cheaper than the quoted price from the service department where they quote MSRP or more. Sill, I couldn't buy the part there and have it walked over to service. To be fair, the repair parts pipeline requires all the parts needed for repair and thus has to carry them for years, which is a real cost.

Tstealth32

You need a Citi card with price rewind. Pay the crazy dealer parts price. Find the same part number online at a lower price. You save money, and get the warranted part from the dealer.

Price rewind/match has saved me thousands the last 2 years. They even match shady online prices, just need to screenshot it.

TFT

A couple of things:
Audi dealerships do not carry this intake manifold in their inventory, it has to be sourced from a national warehouse. There have been times over the years that the parts were actually sourced from Germany. Thankfully because they were for my A8L the shipping was air-freighted and free.
The Audi service rep is the one that actually suggested I buy the part on line. This is not the first time he has done that. When one of the air shocks and compressor failed he suggested i source the parts online. Audi wanted approx $2,000 for the strut I got it on line for $695.
I will soon need new brake pads and rotors. when I discussed this with the rep he again suggested I go on line. He told me that most owners with the S or RS models buy the EBC red pads and bring them in for installation. At least at Audi Chandler this is not a problem. I have a couple of boxes setting in my garage with new pads and rotors waiting until they are needed.

TFT

Just picked up the car after carbon cleaning and new intake manifold install.
HOLY MOLY!!!
It has picked up a bunch of HP on the top end. As long as I've owned this car it always seemed week on the top end, like it was running out of air or gas and that seemed to be the case once you got over 70-80 mph. Now it seems to pull harder as the rpms increase.
It is amazing how strong it runs. I only took it up to 100 mph under hard acceleration and it just kept on pulling.
I am beginning to think there may have always been an issue with the intake manifold.